Field of the Invention
The present invention relates to an image capturing apparatus including an image capturing unit that captures an image of a target object.
Description of the Related Art
Conventionally known projectors project an image (image information) onto an external screen.
Japanese Patent Application Laid-Open. No. 2000-112021 discusses a projection display apparatus including a light source, a lens group, and the like for projecting an image onto a screen, and a screen sensor for detecting a pointer and the like projected on the screen. The screen sensor includes an area sensor, such as a charge coupled device (CCD) sensor, and an imaging lens. The screen sensor detects an amount of light projected on a display area, positions and sizes of the screen and a projected image, a mark pointed on the projection surface by using a laser pointer and the like.
Incidentally, an excessive increase in a temperature of a light source of a projector may shorten the service life of a projector. Thus, cooling mechanisms that cool light sources have been conventionally known. U.S. Pat. No. 8,562,143 discusses a configuration in which a light source is cooled by applying cooling air to the light source using a fan.
Further, Japanese Patent Application Laid-Open No. 2000-112021 discusses a projection display apparatus including a light source for the image projection and a screen sensor (a lens barrel including the area sensor, such as the CCD sensor, and the imaging lens) that are contained in a single casing.
In a more downsized apparatus, an area sensor or a lens barrel is disposed closer to a light source. In such a configuration, the area sensor or the lens barrel has a higher risk of being heated by heat emitted from the light source. When the lens barrel is heated, a refractive index of the lens changes. Further, defocusing occurs due to thermally expansion of the lens barrel. As a result, an imaging performance of the area sensor is degraded. When the area sensor is heated, there is a possibility that photoelectric conversion characteristics of the area sensor may be changed, and thereby noise image information may be obtained.
As such, there is the conventional technique whereby a light source is cooled using a fan. However, the technique is problematic in that the cooling air heated by the light source may be blown onto the area sensor and the lens barrel to heat them and thereby an imaging function may be degraded.